The value of commodities moving by truck decreased by 3.1% in December 2015 compared to December 2014, while the value of air freight decreased by 3.5% and rail by 9.3%, according to a report published by United States of Transportation’s Office of the Assistant Secretary for Research and Technology Bureau of Transportation Statistics, Washington, D.C. Vessel freight value decreased 29.9% and pipeline freight decreased 47.4%, mainly due to the lower unit price of crude oil (a component of mineral fuels), which comprises a large share of the commodities carried by these modes.

Trucks carried 63.4% of U.S.-NAFTA freight and continue to be the most heavily utilized mode for moving goods to and from both U.S.-NAFTA partners. Trucks accounted for $28 billion of the $46.8 billion of imports (60%) and $26.9 billion of the $40 billion of exports (67.3%).

Rail remained the second largest mode by value, moving 15.1% of all U.S.-NAFTA freight, followed by vessel at 6.4%; pipeline at 4.7%; and air at 4.3%. The surface transportation modes of truck, rail and pipeline carried 83.2% of the total U.S.-NAFTA freight flows.

U.S.-Canada freight
The value of U.S.-Canada freight totaled $45 billion in December 2015, down 15.2% from December 2014, as all modes of transportation carried a lower value of U.S.-Canada freight than a year earlier.

Lower crude oil prices contributed to a year-over-year decrease in the value of freight moved between the United States and Canada. Crude oil is a large share of freight carried by vessel and pipeline, which were down 35.2% and 47.4% respectively year-over-year.

Trucks carried 57.3% of the $45 billion of freight to and from Canada, followed by rail at 15.9%; pipeline at 8.4%; air at 4.9%; and vessel at 4.5%. The surface transportation modes of truck, rail and pipeline carried 81.6% of the total U.S.-Canada freight flows.

U.S.-Mexico freight
The value of U.S.-Mexico freight totaled $41.7 billion in December 2015, down 2.4% from December 2014, as two out of the five transportation modes—air and truck—carried more U.S.-Mexico freight value than in December 2014. Freight carried by truck increased by 1.3%, led by shipments of electrical machinery, which were up 7.4%. Air freight value rose 2%, while rail freight value declined 0.1%. Pipeline freight value decreased by 46.5% and vessel freight value decreased by 26.4%, mainly due to lower crude oil prices.

Trucks carried 70% percent of the $41.7 billion of the value of freight transported to and from Mexico, followed by rail at 14.3%; vessel at 8.5%; air at 3.7%; and pipeline at 0.6%. The surface transportation modes of truck, rail and pipeline carried 84.8% of the total U.S.-Mexico freight flows.

In December 2015, the top commodity category transported between the United States and Canada by all modes was vehicles and parts, of which $4.9 billion, or 56.7%, moved by truck and $3.5 billion, or 41.1%, moved by rail.